N,N,N′-trimethylbisaminoethylether (T3MBAEE) is an important chemical compound and can be used as a precursor for the manufacturing of catalysts. In general N,N,N′-trimethylbisaminoethylether is present as a side product in the manufacturing process for N,N,N′,N′-tetramethylbisaminoethylether which is a catalyst used in the production of polyurethane foam. Blends of N,N,N′,N′-tetramethylbisaminoethylether and N,N,N′-trimethylbisaminoethylether are formed when methylamines comprising a mixture of monomethylamine, dimethylamine and trimethylamine are reacted with diethylene glycole over a copper chromite catalyst. The ratio of these materials may vary by a wide range depending on the composition of methylamines (ratio of dimethylamine versus monomethylamine). Due to the fact, that N,N,N′,N′-tetramethylbisaminoethylether and N,N,N′-trimethylbisaminoethylether have boiling points which differ from each other only slightly any distillative purification is extremely difficult.
However, for quality reasons it is important to provide customers with highly purified N,N,N′,N′-tetramethylbisaminoethylether and likewise there is a high economic interest to recover the T3MBAEE because it might be used itself as a starting material for other high valuable chemical components. Derivatisation of T3MBAEE is technically difficult and/or uneconomic because no pure T3MBAEE is available for synthetic purposes. The prior art only provides blends which cause technical problems if recycling of N,N,N′-trimethylbisaminoethylether is required. This is because the separation by distillation will yield a blend of the same materials, however, having a different composition.
U.S. Pat. No. 5,874,483 discloses a method for the preparation of N,N,N′-trimethylbisaminoethylether by reacting dimethylaminoethoxyethanol with monomethylamine in the presence of a Cu/ZnO/Al2O3 catalyst. After distillation of the reaction product a mixture comprising 57.2 weight % N,N,N′-trimethylbisaminoethylether, 37.4 weight % dimethylaminoethoxyethanol and 5.4 weight % of other amines were obtained. Since no pure N,N,N′-trimethylbisaminoethylether can be obtained by the reaction the crude reaction mixture was subsequently derivatised with acrylonitrile which leads to a crude reaction mixture comprising approximately 1% of unreacted N,N,N′-trimethylbisaminoethylether. Even derivatisation of N,N,N′-trimethylbisaminoethylether with acrylonitrile was not successful in yielding a complete separation of the product mixture.
U.S. Pat. No. 7,009,081 B2 discloses a method for converting an amino ether alcohol to an amino ether amine comprising contacting a catalyst containing at least zinc oxide and at least copper oxide or a copper salt with a vapor phase mixture comprising the amino ether alcohol and an amine. In particular, the reaction of dimethylaminoethoxyethanol with monomethylamine or dimethylamine produces N,N,N′-trimethylbisaminoethylether and N,N,N′,N′-tetramethylbisaminoethylether, respectively. Depending on the catalyst system used the ratio of N,N,N′-trimethylbisaminoethylether to N,N,N′,N′-tetramethylbisaminoethylether varies. However, it is not possible to produce pure N,N,N′-trimethylbisaminoethylether.